Calendar/Lightning support is broken on Thunderbird 60.2.1 for French Canadian Locale. It is possible to create new events, but it looks like it is not possible to set time or hours, because time is in format: hh h mm, instead of hh:mm, and lightning or Thunderbird, don't seem to understand time in this format. When trying to select/set time, the time is set back to 0:00 in begin time and end time, after clicking elsewhere on screen.

There is no issue with French (france) locale, the issue seems specific to French Canadian Locale only, as time format for French(france) is like US format: hh:mm.